Opener for clam shells and the like

ABSTRACT

An opener for shell fish such as clams, oysters, mussels, scallops and the like, in which the shell is held on a support with the seam between its shell parts exposed, and a knife is mounted on that support for movement toward and away from the shell, thereby to penetrate the seam, and for further movement to sever the seam along its length, thus permitting the shell to be opened and exposing the meat inside the shell. In one embodiment that further movement generally corresponds to the path of the seam, and in a second embodiment it generally corresponds to a prolongation of the penetrating movement.

United States Patent [1 1 Valentino OPENER FOR CLAM SHELLS AND THE LIKEPrimary Examiner Robert Peshock Attorney Maxwell James and Harold James[57] ABSTRACT An opener for shell fish such as clams, oysters, mussels,scallops and the like, in which the shell is held on a support with theseam between its shell parts exposed, and a knife is mounted on thatsupport for movement toward and away from the shell, thereby topenetrate the seam, and for further movement to sever the seam along itslength, thus permitting the shell to be opened and exposing the meatinside the shell. In one embodiment that further movement generallycorresponds to the path of the seam, and in a second embodiment itgenerally corresponds to a prolongation of the penetrating movement.

24 Claims, 10 Drawing Figures PATENTEU JUL 3 I I975 SHEEI 2 BF 4INVENTOR JQS'EPH V. VIII/777A /fl k ATTORNEY PATENIED L W 3. 748.692

sum a nr 4 INVENTOR JOSEPH M W! [/7 77/70 ATTORNEY PATENIEDJUm ma SHEEI0F 4 OPENER FOR CLAM SHELLS AND THE LlKE This application is acontinuation in part of my earlier application having the same title,Ser. No. 133,212, filed Apr. 12, I971.

The present invention relates to improved apparatus for openingshellfish such as clams, oysters, mussels, scallops and the like. 7

Shellfish are a prized eating delicacy, but they present a very realproblem to the gourmet they are very difficult to open. In order to gainaccess to the edible meat of the animal, it is necessary to open theshell which surrounds that meat. The animal has very strong connectivetissue which secures the two halves of its shell to one another, andthis connective tissue resists attempts to open the shell. Ordinarilythe connective tissue holds the shell parts closely against one anotherwith an appreciable force, so that it is difficult to pry them aparteven a little bit. Even after the shell parts are pried apart slightly,the connective tissue still resists full opening of the shell. Even ifthat connective tissue is penetrated at a localized area, the length ofthe seam between the two shellhalves will still have substantial amountsof connective tissue activetherebetween, so that the shell will stillstrongly resist opening. It is necessary, if the shell is to be opened,that the connective tissue between the two shell halves be cut over all,or at least a very substantial proportion, of the length of the shellseam.

There are those who, after long experience, can open shellfish veryexpeditiously merely by dextrous manipulation of a knife. However, suchindividuals are few in number, and attempts by relatively unskilledindividuals to open clam shells or the like with a knife are generallyunsuccessful, and, perhaps more importantly, constitute a very realhazard. The knife used must be very sharp; unless it is handled withgreat skill the individual may well out himself, and such accidentalcuts are usually relatively serious because of the force which must beexerted on the knife when it is being used.

Shellfish of the kind here under discussion are of various types, theshells of which have different shapes. Moreover, even shellfish within agiven type will vary somewhat in shape and may vary quite radically insize. Accordingly, it is very difficult to devise apparatus which willeffectively perform the shell opening operation and which can be usedwith shellfish of different types or even with shellfish of the sametype which are of different sizes.

Another problem involved in the time required to effect the opening ofthe individual shellfish. Each clam or the like has but a small morselof edible meat. in order to make a dish for a person it is necessarythat a number of such shellfish be opened, and when a plurality ofpeople are planning to eat together the number of shellfish which may beopened are correspondingly multiplied. Since-each shellfish must beindividually opened, the time required to carry out the openingoperation becomes quite appreciable. Any apparatus which cannotexpeditiously accomplish the shell opening operation is of little or nouse.

There is another requirement for devices designed to open shellfish.They must be very readily cleanable, since shellfish residue, ifpermitted to stand, soon becomes quite odoriferous, and an opener whichcannot readily be cleaned would soon become a very unwelcome appliancein a kitchen.

It is a prime object of the present invention to devise a shellfishopener which can be used rapidly and effectively by persons with limitedamounts of skill, and which will be safe in its manner of operation.

It is another object of the present invention to provide such a devicewhich could be used either in a home, where shellfish are opened onlyrelatively infrequently, or in a restaurant, where shellfish opening maybe a very major operation.

It is yet another object of the present invention to devise a shellfishopener which can readily be adapted to function with different types andsizes of shellfish, but which is designed to be manipulated in the samefashion no matter what the type or size of the shellfish may be.

It is yet another object of the present invention to devise such anopener which is simple and sturdy in construction, and which may readilybe assembled and disassembled for purposes of cleaning.

A further object of the present invention is to provide such an openerin which the movement of a knife initially to penetrate the shell seamis accomplished in a precisely controlled manner, thereby facilitatingthe accurate penetration of the seam without fragmenting the shell,after which the seam is further cut to open the shell by means of arapid movement which, because the seam has alrady been penetrated, willeffectively open the shell without fragmentation. I

To these ends, the shell opener of the present invention comprises asupport adapted to engage and hold a shellfish so that the seam betweenthe shell halves isexposed over at least a very substantial portion ofits length. Mounted on the support is a carrier which carries a knife.The knife is adapted to overlie the seam of the shell and to be movablerelative to the carrier toward and away from the shell in a preciselycontrolled manner, thereby initially to penetrate the shell seam and cutthe connective tissue between the shell halves. Thereafter the carrieris moved, and this causes the knife to move along therewith, thereby tosever the connective tissue over a sufficient length to permit the shellto be opened. Because the initial penetration of the seam isaccomplished in a precisely controlled manner, that initial penetrationis achieved without fragmenting the shell, this being desirable so thatthe shellfish meat can be eatenwithout danger. The subsequent cuttingmovement of the knife is carried out rapidly and with a relatively grosstype of motion, but because the knife has already been properly alignedwith the shell, having previously penetrated the seam thereof, thisagain can be carried out without danger that fragments of the shell willbe formed. A single handle is provided, manual manipulation of whichaccomplishes both the movement of the knife toward and away from theshell for penetration purposes and the further movement of the knife tocomplete the opening operapermit it to adapt itself to the shape of theparticular shellfish then being acted on.

To the accomplishment of the above, and to such other objects as mayhereinafter appear, the present invention relates to the construction ofa shellfish opener, as defined in the appended claims and as describedin this specification, taken together with the accompanying drawings, inwhich:

FIG. 1 is a side elevational view of one embodiment of the shell openerof the present invention, showing a shell in place thereon just prior tobeing opened;

FIG. 2 is a top plan view thereof, taken along the line 22 of FIG. 1;

FIG. 3 is a view similar to FIG. 1 but showing the position of the partsafter the knife has been caused to penetrate the shell seam;

FIG. 4 is an end elevational view of the device of FIG.

FIG. 5 is a view similar to FIG. 3 but showing the manner in which thecarrier and knife are moved to sever the connective tissue along thelength of the exposed shell seam;

FIG. 6 is an enlarged fragmentary section showing the manner in whichthe knife is mounted on the carrier;

FIG. 7 is a front elevational view of a second embodiment of the shellopener of the present invention, parts thereof being shown in solidlines in the position which they will assume when the opener is usedwith a smaller shell; and

FIGS. 8, 9 and are cross sectional views taken along the lines 88, 9-9and l0l0 respectively of FIG. 7.

The shell opener of the present invention comprises a support generallydesignated A which is adapted to receive and hold a shell generallydesignated B with the seam 2 between the two halves of the shellexposed. Mounted on the support A is a carrier generally designated Cwhich carries a knife generally designated D. The knife D is initiallymovable relative to the carrier C toward and away from the shell B, sothat different sizes and types of shells can be mounted on the supportA, with the knife B thereafter being moved towards the shell so as topenetrate the connective tissue of the shellfish at the shell seam 2.The carrier C is mounted so as to be movable relative to the support Aand to carry the knife D therewith, thereby causing that knife, after ithas penetrated the shell B, to sever substantial portions of the lengthof the shell seam 2, thereby cutting the connective tissue along thosesubstantial length portions. Then the knife D is withdrawn from theshell B, the shell is removed from the support A, and the shell B canreadily be opened because there is little or nothing left of theconnective tissue which normally tends to retain the shell halvesagainst one another.

In the first disclosed embodiment illustrated in FIGS. l-6 the support Acomprises a pair of parts 4 and 6, each having an exposed portion of itsupper surface, generally designated 8, in registration with one anotherso that a shell B can be grasped therebetween. As there disclosed theshell-engaging surfaces 8 are defined by bodies 9 of soft, compressiblematerial such as sponge rubber, soft rubber or foamed plastic. Meansgenerally designated 10 are provided for adjustably securing supportportions 4 and 6 to one another. As there specifically disclosed, thesupport portion 6 is provided with a rod 12 which is freely slidablewithin an elongated passage 14 in the support portion 4, the latterbeing provided with a set screw 16 which engages the rod 12 and holds itin position. When the device is to be used the set screw 16 is loosened,the parts 4 and 6 are separated, a shell B of desired type and size islocated in 8, space defined between the surfaces [and the support parts4 and 6 are pushed together until the shell B is firmly held in placewith its seam 2 uppermost and exposed. Then the set screw 16 istightened, thus holding the support parts 4 and 6 in adjusted positionwhile those parts firmly grasp and hold the shell B. It is preferred, inorder to increase the reliability with which the shell B is held inposition, both during the adjusting of the support parts 4 and 6 andthereafter, to provide resilient arms 18 on the support part 4, thosearms terminating in shell-engaging enlarged portions 20, the arms 18with their end portions 20 thus serving to hold and to steady the shellB when it is grasped between the support parts 4 and 6.

In the embodiment of FIGS. 1-6 the carrier C comprises an elongatedlever arm 22 which is pivotally mounted on the support part 4 at 24. Itextends well beyond the surfaces 8 of the support parts 4 and 6, andthen has a laterally extending part 26 which extends over theshell-engaging surface 8 and terminates in a sleeve 28 which isinternally threaded. If desired, and as is preferable, a torsion spring30 may be mounted about the pivotal axis 24, with one end 32 thereofanchored in the support part 4 and with the other end 34 thereof activeagainst a side surface of the carrier 22, thereby resiliently to retainthat carrier in a desired position, such as its vertical position.

An externally threaded screw part 36 is threadedly received inside thesleeve 28, that screw part 36 having a tipped portion 38 which extendstoward the shellengaging surfaces 8 of the support parts 4 and 6 and anupper portion 40 which extends away from those shellengaging surfaces 8and terminates in a handle 42. The knife D is mounted on the downwardlyextending tip portion 38 of the threaded part 36. It preferably ismounted thereon so as to have a limited degree of swinging movementrelative thereto. To that end, and as may best be seen in FIG. 6, amounting part 44 extends downwardly from the tip portion 38 of the screwpart 36, and the knife D is pivotally mounted about that part by meansof pin 46. The knife D preferably has a pair of oppositely positioneddownwardly depending sharpened points 48, with both the outer and inneredges of those portions 48 preferably being sharp.

When a given shell B is to be opened, the handle 42 will be rotated soas to lift the knife D sufficiently to clear the particular shell Bwhich is to be operated upon. After that shell B has been clampedbetween the support parts 4 and 6, the carrier 22 being at that time ina vertical position as urged by the spring 30, the handle 42 is rotatedso as to cause the knife D to move downwardly toward the shell seam 2.As this is done, the operator may move the shell B slightly from side toside to ensure that the points of the knife edges accurately penetratethe shell seam 2 without damaging the shell. This operation iscontinued, as shown in FIG. 3,

. until the knife D penetrates the shell seam 2 to an appreciabledegree. As is best seen in FIG. 4, the side surfaces 50 of the knife Dtaper upwardly and outwardly, so that the penetration of the shell seamby the knife D not only cuts the connective tissue but tends to pry orwedge the shell halves apart.

Thereafter, as shown by arrow 52 in FIG. 5, the handle 42 is grasped andmoved laterally to one side and the other, thereby causing the knife Dto traverse a generally arcuate path which substantially conforms to thepath of the shell seam 2. As the knife D thus moves, it cuts theconnective tissue along those portions of the length of the shell seam 2which are thus traversed.

The handle 42 is then rotated in a knife-retracting direction, the knifeD is withdrawn from the shell B, and the shell B can then be removedfrom the support A, usually without having to manipulate the support Ain any fashion, the shell then being readily manually openable merely bypulling the two shell halves apart.

In the embodiment of FIGS. 7-10, the support A comprises base 60 havinga fixed upstanding part 62 with a curved shell-grasping surface 64, andslidably mounted on the base 60 and movement toward and away from thefixed upstanding part 62 is a movable upstanding part 66 having a curvedgrasping surface 68 opposing the surface 64. The surfaces 64 and 68 maybe lined with a soft material such as is designated by the referencenumberal 9 in FIGS. 16, but they are here specifically shown as beingrelatively rigid and provided with shell-edge-receiving grooves 70. Thepart 66 is moved toward or away from the part 62, as indicated by thesolid and broken lines in FIG. 7, in accordance with the size of theshell to be grasped thereby, and the parts 62 and 66 are adapted to beclamped in position by actuating arm 72 which rotates screw 74 movingclamp nut 76 toward and away from a side surface of the horizontal part66' of the part 66, as best shown in FIG. 8.

The carrier C in the embodiment of FIGS. 7-10 com prises plate 78slidably received between bifurcated upwardly extending portions 620 and62b of part 62 and portions 66a and 66b of part 66. Fixed pins 80 and 82cross the space between the bifurcated portions 62a, 62b and 66a, 66brespectively and are received within openings 84 and 86 respectively inthe plate 78, the opening 84 extending vertically and having a widthsubstantially that of the pin 80, the opening 86 also extendingvertically and having a very appreciable lateral width, thereby topermit lateral movement of the part 66 relative to the part 62 toaccommodate shells of different sizes. The plate 78 is normally urged toan upper position by means of springs 88 and 90 mounted respectively inthe spaces between the bifurcated portions 62a, 62b and 66a, 66b, thosesprings permitting downward movement of the carrier C when that isdesired. For guiding purposes the springs 88 and 90 cooperate with rods92 and 94 respectively.

The carrier plate 78, at a point above the shellrecciving space definedbetween the surfaces 64 and 68, is provided with an internally threadedopening 96 within which screw 98 is received, that screw being providedwith a handle 100 at its upwardly extending end, and having the blade Dmounted in any appropriate manner on its downwardly extending end.

With the embodiment of FIGS. 7-10, when a given shell B is to be openedthe handle 100 will be rotated so as to lift the knife D substantiallyto its position shown in solid lines in FIG. 7. The part 66 will bemovedaway from the part 64, the shell will be inserted therebetween, and thepart 66 will then be moved back toward the part 64 until the shell seamis grasped in the notches 70 formed in the shell-grasping surfaces 64and 68. The parts 64 and 66 will then be locked in position throughappropriate manipulation of the handle 72. Thereafter, and while thecarrier C remains in its spring-urged upper position, the handle 100 isrotated so as to cause the knife D to move downwardly toward the shellseam 2. As this is done, the operator maymove the shell B slightly fromside to side to ensure that the knife edge accurately penetrates theshell seam without damaging the shell. This operation is continued untilthe knife D penetrates the shell seam 2 to an appreciable degree. Thisprecision seam penetration operation is essentially the same as thatperformed in connection with the earlier described embodiment.

Thereafter, and as shown by the arrows 102 in FIG. 7, the handle 100 ispushed down, moving the carrier C defined by the plate 78 alongtherewith against the action of the springs 88 and 90, the slots 84 and86 through which the pins and 82 respectively pass permitting thismovement. With this movement the knife D penetrates the seam morecompletely than before and, because of its outwardly tapered shape, suchas is shown in FIG. 4, it positively wedges the shell open, stretchingand breaking enough of the seam membrane which is not actually cut sothat the shell is effectively opened. In this downward movement theoperator may,

'while he holds the knob 100 between his fingers, place the heel of hishand on that portion of the upper surface of the plate 78 which extendsoutwardly and to the right from the handle 100 as viewed in FIG. 7, thusensuring that a firm and strong downward force is applied to the knife Dand that the knife D is moved downwardly rather than merely beingrocked.

Thereafter the downward pressure on the carrier C will be released, thesprings 88 and will restore the carrier C, and with it the knife D, toits upper position, the handle 72 will be manipulated to unlock theparts 62 and 66, those parts can be slid away from one another and theshell B can be removeed from the device. It may or may not be necessaryto rotate the handle to move the knife D further upwardly, dependingupon the degree to which it had previously been moved downwardlyrelative to the carrier C, the extent to which the shell had beenopened, and the precise size of the next shell to be opened.

The parts of the openers here disclosed are extremely sturdy and simple,they are readily exposed for cleaning purposes or for replacement in theunlikely event that any of them should become damaged, the device mayreadily be manipulated and operated with minimal risk of breaking theshell and producing fragments which might be a hazard to those eatingthe meat of the shell fish, and a large number of shells may rapidly andeffectively be opened in a short period of time, particularly where, asis usually the case, the shells being opened at any one time are all ofroughtly the same size.

While but a limited number of embodiments of the present invention havebeen here specifically disclosed, it will be apparent that manyvariations may be made therein, all within the scope of the instantinvention as defined in the following claims.

I claim:

1. A shell opener comprising a support, means on said support forengaging and holding a shell with its seam exposed and extendingsubstantially in a given path, a carrier operatively mounted on saidsupport, ex-

tending beyond said support and movable in a path generally conformingto the path of said seam, and a knife mounted on said carrier so as tobe movable therewith and movable relative thereto toward and away fromsaid shell holding means, whereby said knife may be caused to penetratesaid shell seam by virtue of said relative movement and may then bemoved along said seam to open said shell.

2. The shell opener of claim 1, in which said carrier is pivotallyoperatively connected to said support for arcuate move-ment.

3. The shell opener of claim 2, in which said knife is mounted on saidcarrier for limited swinging movement relative thereto.

4. The shell opener of claim 1, in which said carrier comprises a handlepart extending outwardly from said knife.

5. The shell opener of claim 4, in which said handle part comprises anactuator for positioning said knife relative to said carrier,manipulation of said handle part in one sense causing said knife toshift its position relative to said carrier and thereby move toward andaway from said shell, manipulation of said handle part in another sensecausing said carrier and knife to move together relative to saidsupport, thereby to cut said shell seam along the length thereof.

6. The shell opener of claim 5, in which said carrier is pivotallyoperatively connected to said support for arcuate movement.

7. The shell opener of claim 6, in which said knife is mounted on saidcarrier for limited swinging movement relative thereto.

8. The shell opener of claim 4, in which said carrier is pivotallyoperatively connected to said support for arcuate movement.

9. The shell opener of claim 8, in which said knife is mounted on saidcarrier for limited swinging movement relative thereto.

10. The shell opener of claim 1, in which said support comprises firstand second parts having cooperating shell-gripping surfaces, and meansfor securing said parts to one another in adjustable relative position.

1 1. The shell opener of claim 10, in which said shellgripping surfacesare defined by sponge-like material.

12. In the shell opener of claim 10, resilient means mounted on saidsupport, having free portions located above said shell-grippingsurfaces, and adapted to engage the exposed surface of a shell held insaid opener and to steady the latter.

13. The shell opener of claim 1, in which said carrier comprises an armpivotally mounted on said support, extending beyond said support, andhaving a part overlying said support, screw means threadedly operativelyconnected to said part and having portions extending from said partrespectively toward and away from said support, said knife being mountedon the portion thereof extending toward said support, and a handlemounted on a portion thereof extending away from said support.

14. The shell opener of claim 13, in which said knife is mounted on thecorresponding portion of said screw means for limited swinging movementrelative to said portion.

15. A shell opener comprising a support, means on said support forengaging and holding a shell with its seam exposed, a carrieroperatively mounted on said support and movable in a seam-cuttingdirection, and a knife mounted on said carrier so as to be movabletherewith and also movable relative thereto in a direction toward andaway from said shell holding means, and actuating means operativelyconnected to said knife and active to cause said knife to thus moverelative to said carrier, whereby said knife may be caused to penetratesaid shell seam while said carrier is stationary, after which saidcarrier can be moved to out said seam.

16. The shell opener of claim 15, in which said actuating meanscomprises screw means threadedly mounted in said carrier, said knifebeing operatively mounted on said screw means.

17. The shell opener of claim 16, in which said screw means comprises ahandle part extending from said carrier, rotation of said handle partcausing said knife to move relative to said carrier, movement of saidhandle part in another sense causing said carrier and said knife to movetogether.

18. The shell opener of claim 15, in which said carrier is pivotallyoperatively connected to said support for arcuate move-ment.

19. The shell opener of claim 15, in which said carrier is mounted onsaid support for movement in a given direction toward and away from saidshell holding means.

20. The shell opener of claim 19, in which said handle part comprises anactuator for positioning said knife relative to saidcarrier,manipulation of saidhandle part in one sense causing saidknifeto shift its position relative to said carrier and there-by move towardand away from said shell, manipulation of said handle part in anothersense causing said carrier and knife to move to-gether relative to saidsupport, thereby to out said shell seam along the length thereof.

21. The shell opener of claim 20, in which said carrier comprises a partextending laterally out from said actuator, whereby the actuator may begrasped by the fingers and said part engaged by the heel of theoperators hand.

22. The shell opener of claim 21, in which said heel holding meanscomprises two relatively movable parts, said carrier being operativelyconnected to both of said parts by means permitting movement of saidcarrier in said given direction and means permitting movement of one ofsaid parts relative to said carrier in a direction substantially atright angles to said given direction.

23. The shell opener of claim 19, in which said heel holding meanscomprises two relatively movable parts, said carrier being operativelyconnected to both of said parts by means permitting movement of saidcarrier in said given direction and means permitting movement of one ofsaid parts relative to said carrier in a direction substantially atright angles to said given direction.

24. A shell opener comprising a support, means on said support forengaging and holding a shell with its seam exposed, a carrieroperatively mounted on said support and movable in a seam-cuttingdirection, lengthwise of said seam and a knife mounted on said carrier,said shell holding means comprising two relatively movable parts, saidcarrier being operatively connected to both of said parts by meanspermitting movement of said carrier in said seam-cutting direction andmeans permitting movement of one of said parts relative to said carrierin a direction substantially at right angles to said seam-cuttingdirection.

1. A shell opener comprising a support, means on said support forengaging and holding a shell with its seam exposed and extendingsubstantially in a given path, a carrier operatively mounted on saidsupport, extending beyond said support and movable in a path generallyconforming to the path of said seam, and a knife mounted on said carrierso as to be movable therewith and movable relative thereto toward andaway from said shell holding means, whereby said knife may be caused topenetrate said shell seam by virtue of said relative movement and maythen be moved along said seam to open said shell.
 2. The shell opener ofclaim 1, in which said carrier is pivotally operatively connected tosaid support for arcuate move-ment.
 3. The shell opener of claim 2, inwhich said knife is mounted on said carrier for limited swingingmovement relative thereto.
 4. The shell opener of claim 1, in which saidcarrier comprises a handle part extending outwardly from said knife. 5.The shell opener of claim 4, in which said handle part comprises anactuator for positioning said knife relative to said carrier,manipulation of said handle part in one sense causing said knife toshift its position relative to said carrier and thereby move toward andaway from said shell, manipulation of said handle part in another sensecausing said carrier and knife to move together relative to saidsupport, thereby to cut said shell seam along the length thereof.
 6. Theshell opener of claim 5, in which said carrier is pivotally operativelyconnected to said support for arcuate movement.
 7. The shell opener ofclaim 6, in which said knife is mounted on said carrier for limitedswinging movement relative thereto.
 8. The shell opener of claim 4, inwhich said carrier is pivotally operatively connected to said supportfor arcuate movement.
 9. The shell opener of claim 8, in which saidknife is mounted on said carrier for limited swinging movement relativethereto.
 10. The shell opener of claim 1, in which said supportcomprises first and second parts having cooperating shell-grippingsurfaces, and means for securing said parts to one another in adjustablerelative position.
 11. The shell opener of claim 10, in which saidshell-gripping surfaces are defined by sponge-like material.
 12. In theshell opener of cLaim 10, resilient means mounted on said support,having free portions located above said shell-gripping surfaces, andadapted to engage the exposed surface of a shell held in said opener andto steady the latter.
 13. The shell opener of claim 1, in which saidcarrier comprises an arm pivotally mounted on said support, extendingbeyond said support, and having a part overlying said support, screwmeans threadedly operatively connected to said part and having portionsextending from said part respectively toward and away from said support,said knife being mounted on the portion thereof extending toward saidsupport, and a handle mounted on a portion thereof extending away fromsaid support.
 14. The shell opener of claim 13, in which said knife ismounted on the corresponding portion of said screw means for limitedswinging movement relative to said portion.
 15. A shell openercomprising a support, means on said support for engaging and holding ashell with its seam exposed, a carrier operatively mounted on saidsupport and movable in a seam-cutting direction, and a knife mounted onsaid carrier so as to be movable therewith and also movable relativethereto in a direction toward and away from said shell holding means,and actuating means operatively connected to said knife and active tocause said knife to thus move relative to said carrier, whereby saidknife may be caused to penetrate said shell seam while said carrier isstationary, after which said carrier can be moved to cut said seam. 16.The shell opener of claim 15, in which said actuating means comprisesscrew means threadedly mounted in said carrier, said knife beingoperatively mounted on said screw means.
 17. The shell opener of claim16, in which said screw means comprises a handle part extending fromsaid carrier, rotation of said handle part causing said knife to moverelative to said carrier, movement of said handle part in another sensecausing said carrier and said knife to move together.
 18. The shellopener of claim 15, in which said carrier is pivotally operativelyconnected to said support for arcuate move-ment.
 19. The shell opener ofclaim 15, in which said carrier is mounted on said support for movementin a given direction toward and away from said shell holding means. 20.The shell opener of claim 19, in which said handle part comprises anactuator for positioning said knife relative to saidcarrier,manipulation of said handle part in one sense causing saidknifeto shift its position relative to said carrier and there-by move towardand away from said shell, manipulation of said handle part in anothersense causing said carrier and knife to move to-gether relative to saidsupport, thereby to cut said shell seam along the length thereof. 21.The shell opener of claim 20, in which said carrier comprises a partextending laterally out from said actuator, whereby the actuator may begrasped by the fingers and said part engaged by the heel of theoperator''s hand.
 22. The shell opener of claim 21, in which said heelholding means comprises two relatively movable parts, said carrier beingoperatively connected to both of said parts by means permitting movementof said carrier in said given direction and means permitting movement ofone of said parts relative to said carrier in a direction substantiallyat right angles to said given direction.
 23. The shell opener of claim19, in which said heel holding means comprises two relatively movableparts, said carrier being operatively connected to both of said parts bymeans permitting movement of said carrier in said given direction andmeans permitting movement of one of said parts relative to said carrierin a direction substantially at right angles to said given direction.24. A shell opener comprising a support, means on said support forengaging and holding a shell with its seam exposed, a carrieroperatively mounted on said support and movable in a seam-cuttingdirection, lengthwise of said seam and a knife mounted on said cArrier,said shell holding means comprising two relatively movable parts, saidcarrier being operatively connected to both of said parts by meanspermitting movement of said carrier in said seam-cutting direction andmeans permitting movement of one of said parts relative to said carrierin a direction substantially at right angles to said seam-cuttingdirection.